Search results for "Project"
showing 10 items of 3466 documents
Pre-emption in resource-constrained project scheduling
2008
Abstract The Resource-Constrained Project Scheduling Project (RCPSP), together with some of its extensions, has been widely studied. A fundamental assumption in this basic problem is that activities in progress are non-preemptable. Very little effort has been made to uncover the potential benefits of discrete activity pre-emption, and the papers dealing with this issue have reached the conclusion that it has little effect on project length when constant resource availability levels are defined. In this paper we show how three basic elements of many heuristics for the RCPSP – codification, serial SGS and double justification – can be adapted to deal with interruption. The paper is mainly foc…
A Knowledge-Based System for the Automatic Generation of Plant Shutdown and Startup Schedules
1988
Abstract When the shutdown of a plant, or part of it, has been decided as consequence of a major fault, the generation of a safe shutdown schedule may be, for large and complex plants, a very difficult and delicate task. The same problem may be found when the plant must be restarted after the fault has been repaired, for the generation of a start-up schedule. The use of a knowledge-based system appears to be a suitable answer to this problem, allowing a high level of safety and a very fast generation process. The paper examines the process knowledge that needs to be included in such a knowledge-based system and proposes some knowledge representation forms that appear suitable for the task t…
Justification and RCPSP: A technique that pays
2005
Abstract The objective of this paper is to show that justification is a simple technique that can be easily incorporated in diverse algorithms for the resource-constrained project scheduling problem––improving the quality of the schedules generated without generally requiring more computing time. The results of incorporating this technique in 22 different algorithms are shown. Fifteen of the new algorithms that use double justification outperform seven of the best heuristic algorithms that do not use justification. The tests have been performed on the standard test set j120 for the RCPSP generated using ProGen.
Design and implementation of a course scheduling system using Tabu Search
2002
Abstract Building a course timetable is a difficult and lengthy task which universities devote a large amount of human and material resources to every year. We have developed a computer package to solve this problem. The program runs on a PC and the user may set the objectives and parameters from among a wide range of possibilities. It has a user-friendly interface for the user to input the relevant data and obtain the corresponding results. The optimization process is based on a set of heuristic algorithms. The core is a Tabu Search procedure for which several strategies have been developed and tested in order to get a fast and powerful algorithm. The first tests of the package have produc…
A hybrid genetic algorithm for the resource-constrained project scheduling problem
2008
Abstract In this paper we propose a Hybrid Genetic Algorithm (HGA) for the Resource-Constrained Project Scheduling Problem (RCPSP). HGA introduces several changes in the GA paradigm: a crossover operator specific for the RCPSP; a local improvement operator that is applied to all generated schedules; a new way to select the parents to be combined; and a two-phase strategy by which the second phase re-starts the evolution from a neighbour’s population of the best schedule found in the first phase. The computational results show that HGA is a fast and high quality algorithm that outperforms all state-of-the-art algorithms for the RCPSP known by the authors of this paper for the instance sets j…
Schema-Backed Visual Queries over Europeana and Other Linked Data Resources
2021
We describe and demonstrate the process of extracting a data-driven schema of the Europeana cultural heritage Linked data resource (with actual data classes, properties and their connections, and cardinalities) and application of the extracted schema to create a visual query environment over Europeana. The extracted schema information allows generating SHACL data shapes describing the actual data endpoint structure. The schema extraction process can be applied also to other data endpoints with a moderate data schema size and a potentially large data triple count, as e.g., British National Bibliography Linked data resource.
Toward a European Eco-label brand for residential buildings: Holistic or by-components approaches?
2011
The Eco-label scheme is becoming ever more important in the environmental certification of products and services, especially in light of the recent ambitious aim of containing greenhouse emissions and improving the efficiency of utilizing energy sources. A recently-introduced hypothesis concerns the European Eco-label scheme relating to buildings, in the awareness that the construction industry is of primary importance to the whole economic and social life of states. This scheme should adopt an integrated approach to environmental problems and include construction, day-to-day management, and the possible disposal of building materials, throughout the life cycle of the building. In addition,…
An Analytical Scheme to Characterise the Mathematical Discourse of Biology Tasks
2021
The chapter describes an analytical scheme designed for investigating the mathematical discourse of biology tasks. The scheme was developed in the context of analysing tasks that are part of a fisheries management graduate-level course at a Norwegian university. Grounded in the commognitive perspective, the scheme focuses on the following aspects of the tasks: the mathematical content, its relation to biology discourse and students’ expected engagement with both discourses. To illustrate the potential of analysis, I present and justify the choice of the categories included in the scheme, exemplify its use on one specific task and discuss some of the limitations of this approach to task anal…
An attribute based access control scheme for secure sharing of electronic health records
2016
Electronic health records (EHRs) play a vital role in modern health industry, allowing the possibility of flexible sharing of health information in the quest of provisioning advanced and efficient healthcare services for the users. Although sharing of EHRs has significant benefits, given that such records contain lot of sensitive information, secure sharing of EHRs is of paramount importance. Thus, there is a need for the realization of sophisticated access control mechanisms for secure sharing of EHRs, which has attracted significant interest from the research community. The most prominent access control schemes for sharing of EHRs found in literature are role based and such solutions have…
¿Por qué no vamos a los colegios? Sobre la ausencia de arte actual en la escuela
2017
[EN] This text deepns one of the conclusions drawn from an earlier research, which pointed out the need to claim the action of artists (among other specialists from several areas) in the school context. We know the advantages of community art works. We know all the possibilities of the collaborative projects of artists in different contexts and with different groups; Many countries have statedfunded programs for the participation of artists in Primary and Secondary schools. However, the development of projects dynamized by artists in the school context, are no more than isolated cases in our country. We are currently experiencing an increasing interest in the art world towards education bec…